Storm choke apparatus for submergible pumps

ABSTRACT

Choke valves are provided in association with submergible pumps employed in oil wells or the like to prevent the flow of well fluid toward the well head when the pump is not operating. Differential pressure across the pump is employed to open the valve, and the valve closes automatically when the pump is deenergized. Bottom-hole pressure merely closes the valve more tightly. The pump may be located above or below the valve, and several different choke configurations with different modes of valve operation are disclosed. The storm chokes can be opened by fluid pressure applied from the earth&#39;&#39;s surface in order to permit &#39;&#39;&#39;&#39;killing the well&#39;&#39;&#39;&#39; or flushing sand from the choke.

United States Patent [1 1 ORourke 1 STORM CHOKE APPARATUS FORSUBMERGIBLE PUMPS [75] Inventor: John C. ORourke, Bartlesville,

Okla.

[73] Assignee: TRW, Inc., Cleveland, Ohio [22] Filed: Dec. 7, 1972 [21]Appl. No.: 312,947

[52] US. Cl 415/147, 137/513, 417/295 [51] Int. Cl. F031) 15/02 [58]Field of Search 166/105, 224, 72; 415/146;

[56] References Cited UNITED STATES PATENTS 1,829,704 10/1931 Kruse etal 417/295 2,286,926 6/1942 Parenti 166/105 2,962,099 1 H1960 Clank,.lr. 166/224 2,982,355 5/1961 Rodgers 166/105 3,035,641 5/1962 Page166/72 3,477,507 11/1969 Page, Jr. 166/224 [451 Apr. 30, 1974 3,610,26810/1971 Arutunoff 137/513 2,722,395 11/1955 Boyce 417/295 2,806,433/1957 La Bour 415/147 Primary Examiner-James A. Leppink Attorney, Agent,or Firm-Shapiro and Shapiro [57] ABSTRACT Choke valves are provided inassociation with submergible pumps employed in oil wells or the like toprevent the flow of well fluid toward the well head when the pump is notoperating. Differential pressure across the pump is employed to open thevalve, and the valve closes automatically when the pump is deenergized.Bottom-hole pressure merely closes the valve more tightly. The pump maybe located above or below the valve, and several different choke configwrations with different modes of valve operation are disclosed. The stormchokes can be opened by fluid pressure applied from the earths surfacein order to permit killing the well or flushing sand from the choke.

20 Claims, 3 Drawing Figures PATENTED APR 30 W SHEEI 1 BF 3 5 m \II P J/FIG. 1

iMENIEDAPR 30 IBM SHEET 3 [1F 3 STORM CHOKE APPARATUS FOR SUBMERGIBLEPUMPS BACKGROUND OF THE INVENTION This invention relates to storm chokesand is more particularly concerned with well valves which openautomatically when a submergible pump is actuated but which otherwiseremain closed.

It is common practice to provide an oil well or the like with a deviceknown as a storm choke for blocking the path by which the well fluid mayflow to the earths surface when such flow is not desired. For example,it

is well known to provide well safety or blowout control.

valves which may be operated by a wire line, by hydraulic or pneumaticpressure transmitted from the surface, or in response to well flow rateor pressure parameters to shut off the flow'of well fluid to the surfacewhen such flow would be undersirable or dangerous. See, for example, US.Pat. Nos. 3,265,134; 3,035,641; 3,284,174; 3,090,433; 3,568,768;3,273,606; 2,962,099; and 3,477,507. Devices of this type tend to becomplicated, expensive, unwieldy, and/or unreli-' able. It is known toemploy various types of valves in conjunction with pumps, as shown, forexample, in US. Pat. Nos. 1,775,480; 2,722,395; 3,610,268; and1,329,704, but such devices are not suited for use as effective stormchokes in conjunction with submergible pumps.

SUMMARY OF THE INVENTION It is accordingly a principal object of thepresent invention to provide improved storm choke apparatus or the like.

Another object of the invention is to provide storm chokes which openautomatically in response to the operation of an associated submergiblepump..

A further object of the invention is to provide storm chokes which areattached to or part of the submerged inlet or outlet housing of asubmergible pump and in which all of the choke parts are adjacent to thepump and not dependent upon connections to distant operators.

Yet another object of the invention is to provide storm chokes of theforegoing type which are normally closed by biasing springs and whichremain firmly closed under bottom-hole pressure, but which are readilyopened in response to differential pumping pressure.

Briefly stated, the storm chokes of the invention employ valvesassociated with submergible pumps, which may be located above the valveor below the valve. When the pump is actuated, the differential pressureacross the pump is applied to a valve operator which opens the valve.Reciprocating piston operators are preferred, and in one embodiment themoving valve member itself constitutes the operator piston. In otherembodiments the pump output pressure is applied to one side of theoperator piston through passages in a wall of the choke housing or inthe pump shaft, the pposite side of the piston being exposed to the pumpinput pressure.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be furtherdescribed in conjunc tion with the accompanying drawings, whichillustrate preferred and exemplary embodiments, and wherein:

FIG. I is a contracted longitudinal sectional view of a first embodimentof the invention; I FIG. 2 is a longitudinal'sectional view of a secondembodiment of the invention; and

FIG. 3 is a longitudinal sectional view of a third embodiment of theinvention. 4

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings, andinitially to FIG. 1 thereof, storm choke apparatus of the inventioncomprises an elongated tubular housing 10 of generally cylindricalshape. The lower end of the housing is provided with an opening 12circumscribed by a valve seat or sealing washer l4 engaged by adisc-like main valve member 16. Valve member 16 is supported upon ashaft 18 which is reciprocatively mounted in a bearing sleeve 20 formedat the lower end of a chamber 22, which is supported in the housing 10by means of a spider 24. When the valve member 16 is closed against theseat 14, the space within the housing 10 at one-side of the valve memberis isolated from the space at the opposite side of the valve member.Thus, if the-housing 10 is submerged in the fluid of a well, forexample, the fluid is prevented from entering the housingwhen valvemember 16 is closed. The valve member 16 isnormally biased closed by acoil spring 26 which surrounds rod 18 and applies'a force between an endof bearing sleeve 20 and a piston 28 fixed to shaft 18. The piston iscupshaped and is arranged to reciprocate within chamber 22, a seal tothe chamber wall being provided by means of an O-ring 30. A furthershaft 32 is supported for reciprocation through shaft 18 and has one endattached to an inverted cup-shaped piston 34 supportedfor reciprocationwithin piston 28 and provided with an O- ring seal 36 between thepistons. A coil spring 38 normally biases piston 34 away from piston 28.The opposite end of shaft 32 is provided with apriming valve element 40having an O-ring 42 which seals against the bottom of valve member 16.One or more passages 44 extend through the valve member 16 and areopened to the space below valve member 16 when valve element 40 isopened, shaft 32 being grooved near its lower end to provide paths forfluid to enter the passages 44.

Located in housing 10 above the chamber 22 is a submergible fluid pumpgenerally designated by reference numeral 46. The pump is preferably ofthe centrifugal type, comprising a central pump shaft 48 on whichimpellers 50 are mounted. The impellers cooperate with diffusers 52mounted on the housing 10. The pump shaft 48 is supported upon bearingspiders 24 and 54. The upper end of the pump shaft may be splined forcoupling to a similar shaft section of an additional (or severaladditional) pump stages. The upper end of the pump shaft (or theuppermost section thereof) may be driven by an electric motor (notshown) located in the housing 10 or in a housing fixed to the uppermoststage of the pump. Pumps of the type illustrated are disclosed, forexample, in US. Pat. Nos. 2,775,945; 2,270,666; and 2,236,887. An O-ringseal 56 is provided at the bottom of the pump shaft to prevent leakagein'to the chamber 22 The output side of pump 46 is connected to chamber22 above piston 34 by a longitudinal passage 58 through the pump shaft,a transverse admission port being provided at 60. The entire pumpinstallation, including the choke, pump stages, motor, and auxiliaryapparatus may be suspended in a well from a cable, as taught, forexample, in Pat. Nos. 3,672,795; 3,468,258; and 3,411,454, and the fluiddischarge of the pump may flow to the surface through the well casing ora liner, as disclosed in those patents, or through a conventional tubingstring. This type of installation may also be used in the otherembodiments described hereinafter.

In operation, it is assumed that housing is submerged in and containswell fluid. When' the pump 46 is actuated, the output pressure isapplied through passage 58 to the upper side of piston 34, moving thispiston downwardly in piston 28 and moving valve element 40 so as toexpose the passages 44 to the well fluid below valve member 16. Theslight amount of fluid displaced by movement of piston 34 in piston 28passes between shaft 32 and shaft 18 (which fit loosely enough or areprovided with longitudinal grooves). Only very slight movement of piston34 is required to open valve element 40 and to permit well fluid toenter the passages 44. Thus primed, the pump continues to operate,driving piston 34 downwardly into engagement with piston 28. Piston 28then moves downwardly to open the main valve member 16 and provide fullflow through the main valve and through housing 10 to the pump dischargehead. Fluid trapped in chamber 22 below piston 28 is vented by means ofa vent 62, which is branched to provide a recirculatory path indicatedby. arrow A. The recirculation tends to reduce the upward force onpiston 28 which would otherwise be exerted by well fluid rushing intothe chamber 22 by means of the vent.

As long as the pump is operating, the differential pressure across thepump is sufficient to maintain the main valve 16 open against the biasspring 26, the top of pistons 28 and 34 being subjected to the outputpressure and the bottom of the pistons being exposed to the inputpressure of the pump. Enough stages of impellerdiffuser units areprovided below port 60 to ensure that the differential pressure exertedupon the valve operator in chamber 22 is sufficient to open the mainvalve 16 and to maintain the valve open during pumping. Whenthe pump isde-energized, however, the return springs 26 and 38 move pistons 28 and34 upwardly, closing valve member 16 against its seat and closing valveelement 40 against valve member 16. Bottomhole pressure exerted againstlower surfaces of the valve structure merely closes the valve moretightly. However, valve member 16 may be opened by fluid pressureapplied to the top of the valve member from the earth's surface in orderto kill the well" or to flush sand from the vicinity of the valvemember.

In order to avoid the need for the rotary seal 56 at the bottom of thepump shaft, the embodiment of FIG. 2 may be employed. This embodiment isgenerally similar to that of FIG. 1, as indicated by the referencecharacters employed, but communication between the chamber 22 and theoutput side of the pump 46 is provided by passages 64 and 66 formed in atransverse partition 68 and by a longitudinal passage 70 formed in thewall of the housing 10. Partition 68 has main flow passages 69. It issimpler to provide a long passage 70 in a long housing rather than along passage 58 in a long pump shaft, as in FIG. 1. Passage 70 may beformed as a longitudinal groove inthe inner surface of the side wall ofthe housing 10, the open side of the groove being covered by the outersurface of the diffusers 52 (only some of which are shown).

FIG. 3 illustrates an embodiment intended for use with a pump which ismounted below the storm choke, the pump'being indicated diagrammaticallyat 116 and the storm choke housing being indicated at 118. The pump maybe of the type shown in the aforesaid Pat. Nos. 2,270,666 and 2,775,945,for example, driven by an electric motor from below. Housing 118 andpump 116 are suspended in the well fluid as stated above, the pumphaving inlet ports exposed to the well fluid outside of housing 118. Theupper portion of the housing is provided with a cylindrical head 120having a depending wall 122 spaced inwardly from the side wall ofhousing 1 18 to provide an annular space 124 for reception of acylindrical valve member 126. Chamber 124 above the valve member isvented to the outside of housing 118 by a pssage 127. Valve member 126is normally urged downwardly into engagement with a circular groovevalve seat 128 by a series of coil springs 130. The side walls of thevalve seat'and the lower edges of the valve member 126 preferably havemating tapers as shown. Valve seat 128 is formed in the top surface of atransverse partition 132 having a series of circumferentially spacedlongitudinal passages 134 extending from space 136 to the valve seatregion.

When the pump is not energized, valve member 126 is held closed by thereturn springs and by the bottom-hole pressure exerted upon the top wallof the valve member, the area of the top wall exposed to the bottom-holepressure through vent 127 being substantially greater than the area ofthe lower wall of the valve member 126 exposed to the bottom-holepressure through passages 1 34. When the pump is operating, however, theoutput pressure in space 136 is transmitted through passages 134 to thebottom of valve member 126, the top of the valve member being exposed totheinput pressure through passage 127, moving the valve member upwardlyagainst the bias of springs 130 to open the valve and to permit fullflow into the space 138.

Back flushing to kill the well or to remove sand or the like in thevicinity of valve member 126 and its valve seat may be provided by meansof a normally closed poppet valve 140. The poppet valve controlspassages 142 extending through the partition 132' and is normally closedby a return spring 144 and by the bottomhole pressure. When it isdesired to kill the well or to flush the storm choke, brine is pumpedinto the space 138 from above, and the pressure on the poppet valve 140exerted through the passages 142 is sufficient to open the valve.

While preferred embodiments of the invention are shown and described, itwill be apparent to those skilled in the art that changes can be made inthese embodiments without departing from the principles and spirit ofthe invention, the scope of which is defined in the'appended claims.

The invention claimed is:

1. Storm choke apparatus for use with submergible pump means, comprisinga tubular housing associated with said pump means and adapted to besubmerged in a fluid to be pumped therethrough, valve means supportedupon said housing and having a movable valve member which, when in aclosed position, isolates a space in said housing at one side of saidmember from a space at a different side of said member, with at leastsaid different side of said valve member exposed to said fluid to bepumped, operating means coupled to said valve member and responsive todifferential pumping pressure across said pump means for moving saidvalve member to an open position for providing communication betweensaid spaces, means coupled to said valve member for moving said valvemember to a closed position in the absence of said differential pumpingpressure, and means for maintaining said valve member closedirrespective of the pressure of said fluid at said different side ofsaid valve member. v

2. Apparatus in accordance with claim 1, wherein said operating meanscomprises piston means and means for subjecting opposite sides of saidpiston means to'said differential pumping pressure.

3. Apparatus in accordance with claim 2, wherein said pump means islocated in said housing at said one side of said valve member forpumping fluid away from said valve member, said piston means beinglocated in a chamber at said one side of said valve member.

4. Apparatus in accordance with claim 3, wherein said pump meanscomprises rotary pump elements fixed to a shaft in said housingextending along the length thereof, said chamber being located betweenan end of said shaft and said valve member.

5. Apparatus in accordance with claim 4, wherein said chamber isconnected to the output of said pump means by a passage extendingthrough and along said shaft.

6. Apparatus in accordance with claim 4, wherein said chamber isconnected to the output of said pump means by a passage extending alonga wall of said housing.

7. Apparatus in accordance with claim 3, wherein said valve member hasan operating rod connected to said piston means and extending into saidchamber.

8. Apparatus in accordance with claim 3, wherein said valve meanscomprises a priming valve element which is movable to provide restrictedcommunication between said spaces before movement of said valve memberprovides communication between said spaces.

9. Apparatus in accordance with claim 8, wherein said piston meansincludes a pair of relatively movable pistons for first opening saidpriming valve element and for then opening said valve member.

10. Apparatus in accordance with claim 8, wherein said valve member issupported upon a shaft movable into and out of said chamber, said valveelement is supported upon a shaft supported upon the first mentionedshaft, and wherein said valve member has a passage therethroughcontrolled by said valve element.

11. Apparatus in accordance with claim 8, wherein said valve member andsaid valve element are springbiased to closed positions. i

12. Apparatus in accordance with claim 3, wherein the input side of saidpump means is connected to said chamber at one side of said piston meansby a vent through a wall of said chamber, said'vent having means forproviding a recirculating path thereat to reduce the force upon saidpiston means by fluid entering the vent.

13. Apparatus in accordance with claim 1, wherein said means for movingsaid valve member to a closed position comprises a biasing spring.

14. Apparatus in'accordance with claim 1, wherein said pump means islocated at said different side of said valve member for applying theoutput pressure of said pump means directly to said different side ofsaid valve member to move said valve member away from a cooperatingvalve seat.

15. Apparatus in accordance with claim 14, wherein said means for movingsaid valve member to said closed position comprises means forspring-biasing said valve member against its seat.

16. Apparatus in accordance with claim 15, wherein said means formaintaining said valve member closed comprises a surface of said valvemember exposed to the pressure of said fluid to be pumped, said surfacehaving greaterarea than the surface of the valve member exposed to saidfluid at the opposite side.

17. Apparatus in accordance with claim 16, wherein said valve member isa cylinder having an end portion engaging said seat and wherein saidseat is formed in a partition dividing said housing transversely andhaving passage means therethrough terminating at said seat.

18. Apparatus in accordance with claim 17, wherein said partition has afurther passage therethrough interiorly of said valve member, saidfurther passage being normally closed by a further valve member whichmay be opened against the bias of a spring by fluid pressure exertedupon said further valve member through said further passage from abovesaid partition.

19. Apparatus in accordance with claim 1, further comprising means forproviding communication between said spaces in response to fluidpressure exerted in said housing at said one side of said valve member.

20. Apparatus in accordance with claim 19 wherein the last-mentionedmeans comprises means for applying fluid pressure to said valve memberat said one side to move said valve member to an open position.

1. Storm choke apparatus for use with submergible pump means, comprisinga tubular housing associated with said pump means and adapted to besubmerged in a fluid to be pumped therethrough, valve means supportedupon said housing and having a movable valve member which, when in aclosed position, isolates a space in said housing at one side of saidmember from a space at a different side of said member, with at leastsaid different side of said valve member exposed to said fluid to bepumped, operating means coupled to said valve member and responsive todifferential pumping pressure across said pump means for moving saidvalve member to an open position for providing communication betweensaid spaces, means coupled to said valve member for moving said valvemember to a closed position in the absence of said differential pumpingpressure, and means for maintaining said valve member closedirrespective of the pressure of said fluid at said different side ofsaid valve member.
 2. Apparatus in accordance with claim 1, wherein saidoperating means comprises piston means and means for subjecting oppositesides of said piston means to said differential pumping pressure. 3.Apparatus in accordance with claim 2, wherein said pump means is locatedin said housing at said one side of said valve member for pumping fluidaway from said valve member, said piston means being located in achamber at said one side of said valve member.
 4. Apparatus inaccordance with claim 3, wherein said pump means comprises rotary pumpelements fixed to a shaft in said housing extending along the lengththereof, said chamber being located between an end of said shaft andsaid valve member.
 5. Apparatus in accordance with claim 4, wherein saidchamber is connected to the output of said pump means by a passageextending through and along said shaft.
 6. Apparatus in accordance withclaim 4, wherein said chamber is connected to the output of said pumpmeans by a passage extending along a wall of said housing.
 7. Apparatusin accordance with claim 3, wherein said valve member has an operatingrod connected to said piston means and extending into said chamber. 8.Apparatus in accordance with claim 3, wherein said valve means comprisesa priming valve element which is movable to provide restrictedcommunication between said spaces before movement of said valve memberprovides communication between said spaces.
 9. Apparatus in accordancewith claim 8, wherein said piston means includes a pair of relativelymovable pistons for first opening said priming valve element and forthen opening said valve member.
 10. Apparatus in accordance with claim8, wherein said valve member is supported upon a shaft movable into andout of said chamber, said valve element is supported upon a shaftsupported upon the first mentioned shaft, and wherein said valve memberhas a passage therethrough controlled by said valve element. 11.Apparatus in accordance with claim 8, wherein said valve member and saidvalve element are spring-biased to closed positions.
 12. Apparatus inaccordance with claim 3, wherein the input side of said pump means isconnected to said chamber at one side of said piston means by a ventthrough a wall of said chamber, said vent having means for providing arecirculating path thereat to reduce the force upon said piston means byfluid entering the vent.
 13. Apparatus in accordance with claim 1,wherein said means for moving said valve member to a closed positioncomprises a biasing spring.
 14. Apparatus in accordance with claim 1,wherein said pump means is located at said different side of said valvemember for applying the output pressure of said pump means directly tosaid different side of said valve member to move said valve member awayfrom a cooperating valve seat.
 15. Apparatus in accordance with claim14, wherein said means for moving said valve member to said closedposition comprises means for spring-biasing said valve member againstits seat.
 16. Apparatus in accordance with claim 15, wherein said meansfor maintaining said valve member closed comprises a surface of saidvalve member exposed to the pressure of said fluid to be pumped, saidsurface having greater area than the surface of the valve member exposedto said fluid at the opposite side.
 17. Apparatus in accordance withclaim 16, wherein said valve member is a cylinder having an end portionengaging said seat and wherein said seat is formed in a partitiondividing said housing transversely and having passage means therethroughterminating at said seat.
 18. Apparatus in accordance with claim 17,wherein said partition has a further passage therethrough interiorly ofsaid valve member, said further passage being normally closed by afurther valve member which may be opened against the bias of a spring byfluid pressure exerted upon said further valve member through saidfurther passage from above said partition.
 19. Apparatus in accordancewith claim 1, further comprising means for providing communicationbetween said spaces in response to fluid pressure exerted in saidhousing at said one side of said valve member.
 20. Apparatus inaccordance with claim 19 wherein the last-mentioned means comprisesmeans for applying fluid pressure to said valve member at said one sideto move said valve member to an open position.